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Adding :default => true to boolean in existing Rails column
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change_column is a method of ActiveRecord::Migration, so you can't call it like that in the console.
If you want to add a default value for this column, create a new migration:
rails g migration add_default_value_to_show_attribute
Then in the migration created:
# That's the more generic way t...
What are the GCC default include directories?
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There is a command with a shorter output, which allows to automatically cut the include pathes from lines, starting with a single space:
$ echo | gcc -Wp,-v -x c++ - -fsyntax-only
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.8.2/include-fixed"
ignori...
How to append to a file in Node?
...s, you can use appendFile, which creates a new file handle each time it's called:
Asynchronously:
const fs = require('fs');
fs.appendFile('message.txt', 'data to append', function (err) {
if (err) throw err;
console.log('Saved!');
});
Synchronously:
const fs = require('fs');
fs.appendFile...
jquery how to empty input field
...0' max="10" value="5"></input>? I guess said differently, are you allowed to set a numeric input to be blank?
– Kevin Wheeler
Jun 10 '15 at 21:49
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How to do an instanceof check with Scala(Test)
I'm trying to incorporate ScalaTest into my Java project; replacing all JUnit tests with ScalaTests. At one point, I want to check if Guice's Injector injects the correct type. In Java, I have a test like this:
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Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '=
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SET @rUsername = ‘aname’ COLLATE utf8_unicode_ci; -- COLLATE added
CALL updateProductUsers(@rUsername, @rProductID, @rPerm);
Option 2: add COLLATE to the WHERE clause:
CREATE PROCEDURE updateProductUsers(
IN rUsername VARCHAR(24),
IN rProductID INT UNSIGNED,
IN rPerm VARCHAR(16...
How to invert a grep expression
The following grep expression successfully lists all the .exe and .html files in the current directory and sub directories.
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API pagination best practices
...principles can be followed):
{
"data" : [
{ data item 1 with all relevant fields },
{ data item 2 },
...
{ data item 100 }
],
"paging": {
"previous": "http://api.example.com/foo?since=TIMESTAMP1"
"next": "http://api.example.com...
How to clear the cache in NetBeans
... me absolutely crazy, trying to track down bugs for hours that weren't actually there -- the class with the main method was not being found, and some custom exception classes were not being recognized as implementing Throwable... I just deleted the stupid cache, and now all of it works fine.
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How to resize a tableHeaderView of a UITableView?
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+1 This worked for me. Calling 'setTableHeaderView' after your subview has changed size is the key. The problem is, my subview changes size over a second as an animation. Now I'm trying to figure out how to animate the tableHeaderView with it.
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